Much of the area surrounding a rolling mill is provided with rails, runways and tracks to facilitate the shifting of, for example, mill rolls, coil cars and the like. Generally these rails and tracks are below the normal level of the workshop floor in order to accommodate the working position of such rolls, cars, etc.
Safety precautions demand that, when the rails and tracks are not in use for shifting the mill components, removable floor plates must be provided. However, in some cases, for example, where coil cars carrying coils of strip from the delivery end of the rolling mill stand to suitable conveying and storage facilities it is necessary that there be an opening in the floor area to accommodate that part of the coil car that extends upwardly through floor level. Thus an open area of floor approximately equal to the width of the coil car and extending for the length of travel of the car is present in such cases and there are periods during maintenance procedures, and indeed during initial erection of the mill, when there is a danger of workmen falling through the opening into the void below.